Monthly Archives: June 2011

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In April 2011 funding shortfalls in the budget of the State of California resulted in the ‘hibernation’ of the Allen Telescope Array (ATA) north of San Francisco. The ATA was primarily used by the Search for Extraterrestrial Intelligence (SETI) Institute, a not-for-profit scientific organisation that investigates the origin and nature of life in the universe. Scanning the sky for radio signals from distant alien civilisations, the ATA was an integral tool in our quest to uncover some of the mysteries of our astronomical neighbourhood and to answer a fundamental paradox that has puzzled scientists for over 50 years. Where is everyone? Everything we observe about the nature of universe suggests that life, and eventually technologically advanced civilisations, should be prevalent across the cosmos, yet we have no evidence suggesting that life exists anywhere except here on Earth.

What does this apparent isolation say about us and our planet? Are we the product of an extremely fortunate evolutionary accident resulting from the interplay between our astronomical and planetary environment? On some distinguishable level, the search for other intelligent species is a thinly veiled search for our own place, both physically and philosophically and convincing proof of a co-existent alien civilisation would most likely have significant social, political and religious ramifications as well as the potential to cause deep psychological distress at the level of the individual. I have no doubt however, that religious and philosophical doctrines will be reinterpreted by scholars and priests to incorporate these monumental findings in an effort to remain pragmatic and to provide guidance for their respective followers and adherents

We have nothing to fear when we listen. Could there be a more relevant or important allocation of public money than to attempt to answer some of the most fundamental questions of our time? Who are we, where did we come from and are we alone? Are we the only extant advanced civilisation in the universe? Are we the only species capable of uncovering the meaning behind their very existence at a level otherwise completely out of the reach of most organisms?

Or, like a moth alone in the dark are we seeking the comforting light of ignorance; is it better not to know at all rather than to uncover the true scale of our isolation? The burden of the knowledge that help will not come from elsewhere to save us from ourselves may be, for some, too much to bear. The weight of our responsibility to ourselves, our children and our planet will put strain on our collective psyches; mired by loneliness on an unprecedented, truly universal the scale we have only ourselves to blame for our significant shortcomings and failures.

But with this knowledge also comes perspective. Perhaps this will be the perspective required to finally rid ourselves of our incessant propensity to view different races, genders or ethnic groups of our species with contempt, mistrust and hostility. As the only species able to discover and preserve the secrets of the universe for future generations, or future civilisations, we owe it to ourselves and our children to unite as a single species with a truly global heritage.

Above is the image known as the Pale Blue Dot. It was taken by Voyager 1 in 1990 as the spacecraft was leaving the Solar System on its indefinite journey into interstellar space. At over 40 astronomical units (AU), or 6 billion (that’s 6 x 109) kilometres from Earth, the image that was beamed back to us is incredible in its portrayal of our tiny world against the vastness of the cosmos. You are on the tiny blueish pixel, centre right, seemingly illuminated by a beam of light. Although taken two decades ago, I feel that this image is still as significant and poignant as when it was first released.

The image was the inspiration for Pale Blue Dot, a book written in 1994 by renowned cosmologist and science populariser Carl Sagan. Rarely has a work of non-fiction elicited such a powerful emotional response as Pale Blue Dot. Sagan’s reputation as a distinguished author as well as respected scientist was justly deserved; his prose is beautiful, almost poetic in its fluency and rich in vivid imagery and clarity. In particular the opening chapters, entitled ‘Wanderers’ and ‘You Are Here’, are some of the finest examples of science writing I have ever had the pleasure of reading. Sagan’s interpretation of the significance of the above image is so powerful that little I can say here to paraphrase will do his delivery justice.To illustrate my point I will reproduce one of my favourite passages from the book:

“From this distant vantage point, the Earth might not seem of particular interest. But for us, it’s different. Look again at that dot. That’s here, that’s home, that’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar,” every “supreme leader,” every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.”

The reason that these words are so striking is that they epitomise the ability of science to amaze and humble, but also to provide sensible perspective when tackling difficult questions and to reconcile our differences in opinion and ideology. It is often said that a life dedicated to science makes you cold, pessimistic and unattached; absorbed in grey objectivity and burdened by the realisation of the insignificance and futility of our fleeting existence. This book, and in particular this paragraph, prove otherwise. These words are truisms, not empty conjecture, but rather statements of fact catalysed by the perspective garnered from the above image. Earth is a small watery planet in an otherwise uninteresting star system, itself tucked away in a remote corner of a common barrel-spiral galaxy. It is the only home we have ever known and we therefore have a responsibility to care for it and each other, because on the scale of the universe our differences are minuscule and unidentifiable, our existence brief and uneventful and our impact on the vastness of space, practically nil. No religion was required to reach this conclusion, no scripture needed, no proverbs recited or prayers offered. These words were penned by the careful hand of science, yet they dispel our fundamentally flawed sense of self-importance and reveal our basic evolutionary solidarity with each other as well as with all other terrestrial organisms, past and present, that we have had the privilege to share our planet with.

Our desperate isolation, so clearly revealed, is almost painful to comprehend. Our species’ egotistical machinations pale in comparison to the disproportionate emptiness of space. Our fragile, fleshy frames are much too delicate to withstand the abuses of even interplanetary travel; our cells and DNA destroyed by radiation, our bodies and minds distorted by the passage of time and our lungs suffocated by vacuum and cold. The logical and philosophical constructions that have served us so well in the past break down – the anthropic principal, the Fermi paradox and the Drake equation are all examples of how little we know about what is out there, and how incapable we are of providing a conclusive answer in the near future. We lack the technology to leave, barely demonstrate the responsibility and insight to justify the exploration of other planets and are probably centuries away from considering their colonisation. Firmly rooted to our contemporary astronomical location, for now at least, we are alone in the dark.I would urge every person on our planet to read this book. It has humbled me, but also made me proud to be a member of a species that has ventured out into the cosmos, landed on other planets and sent messages to the stars. Voyager 1 remains a testament to human engineering, currently the most distant man-made object from the Earth (at 113 AU) and still obediently cruising through interstellar space in perfect working order 33 years after launch. We clearly possess great potential but there is a chance that we will squander these opportunities in their infancy if we remain focused on differences in race, religion and culture. These are inconsequential and vitriolic human constructions which will stunt our growth as a species and keep us perpetually rooted in the anachronistic superstitions and philosophies of the past. My advice would be to try to keep the above paragraph fresh in your mind, its message floating gently through your subconscious, quietly reminding you to maintain a rational perspective regarding the struggle for our continued existence whilst seeking to dispel our unfortunately innate tendency towards ignorance and presumption.

Well, it sure is quiet around here. Our astronomical neighbourhood is very much a sleepy suburb on the outskirts of the stellar conurbation that is the Milky Way galaxy, our quiet corner of the cosmos is mostly inhabited by middle-aged stars like our Sun and their teenage planetary families. Few stars are born out here in galactic suburbia, and a few are close to death.

So far, Earth is the only planet we are aware of that harbours life of any kind. That does not necessarily mean that life does not exist on other planets, only that we have yet to discover conclusive proof of its existence. What does this apparent isolation tell us about the Earth? Is it possible to infer that our planet’s orbital, geophysical or astronomical environment is in some way unique or especially conducive to the synthesis of precursor proteins essential for life?

Upon considering these questions, a fundamental limitation presents itself. At present our catalogue of known extra-solar planets is populated by an ever-growing 562 members in 471 star systems. Due to limitations in contemporary astronomical technology and survey capabilities, none of these planets appear to be suitable proxies for Earth; most being too large or too far from their parent star. Smaller, Earth-sized planets are difficult to detect using the indirect methods currently employed by astronomers carrying out exoplanet surveys but improving observational technology may resolve these issues in the near-future.

However, this means that at present we have a sample size for life-harbouring planets of n=1, and as any statistician will tell you this is a very unrepresentative sample indeed. Therefore, it is difficult to infer any meaningful conclusion regarding the likely distribution of life in the Universe based on just this one planet. However, our insatiable curiosity tends to require us to make this assumption and this unfortunate circumstance gives rise to the many guises of the anthropic principal. The universe is as it is because we observe it to be so; if conditions in our solar system had been slightly different we may never have evolved the intelligence required to develop sentience and ask questions pertaining to our existence in time and space in the first place. All of our conclusions as to the nature of the universe have to be compatible with the life currently known to exist within it. As products of our astronomical environment, our existence remains permanently and irreconcilably incorporated into the logical framework of our understanding.

To most people, the fact that we have no discovered life on other planets is not surprising. Philosophy and religion have constructed elaborate logical mechanisms to explain our apparent isolation and confirm our fundamental, almost universal centrality and importance as an intelligent species. However, given the fact that there are possibly 1024 stars in the observable universe, it is certainly a statistical possibility that another Earth-like planet exists somewhere out there and that intelligent life may be flourishing elsewhere in the vastness of the cosmos. At least there is no reason, be it physical or chemical, it shouldn’t be possible.

Again, however, our sampling bias presents us with another problem; our entire understanding of life is formulated by studying that which exists on the Earth. The molecular backbone of terrestrial biochemistry is based on carbon and the effectiveness of liquid water as a solvent, and we therefore assume, not unreasonably given the ubiquity of water and carbon compounds in space, that is will be the likely form that extraterrestrial life will take. It is hypothetically possible however, that other forms of biochemistry may exist to exploit different planetary environments, using different solvents and electron donors, or operating on a spatial or temporal scale that would be difficult to reconcile with our understanding of life.

However, it is also equally possible that we are in fact the only intelligent life ever to have emerged in the temporal and/or spatial dimension that we inhabit; the evolution of our superlative intellect may only possible under very limited, serendipitous and fortunate circumstances, the kind of which has never arisen on any other planet in the past. The evolution of simple life may be a relatively easy step; intelligence however may be another matter. We may therefore be sole custodians of the meaning of life, even if we haven’t uncovered it yet. In this case we have an enormous responsibility to protect and preserve our planet for future generations who may be better equipped technologically to answer these fundamental questions regarding our existence and uncover the deep-seated meaning embedded in our seemingly chaotic existence.

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Awards

Short-listed for the Wellcome Trust Science Writing Prize 2012:
For this article.

Welcome!

Astrobiology and the study of planets throughout the galaxy deal with some of the most profound questions regarding our existence: where did we come from, are there other worlds like ours out there, and are we alone?

I don't profess to be able to answer these questions, but that doesn't stop me from cobbling together some loosely coherent thoughts to share with interested readers. I find it helps me to maintain a cosmic perspective.

I can also be found at the University of East Anglia, where I am completing a PhD in the Centre for Ocean and Atmospheric Science broadly focussed on planetary habitability, astrobiology and global biogeochemical cycling on Earth.

I'm a Science Collaborator at the University of Puerto Rico at Arecibo's excellent Planetary Habitability Laboratory. Visit the PHL website for in-depth habitability assessments and exoplanet visualisation.

I am also a committee member of the Astrobiology Society of Britain. Visit the ASB website for more information about astrobiology in the UK:

Please feel free to drop me an email or comment and let me know what you think of the site (I host and design it myself, so feedback is appreciated) and the articles, or just to say hi.

Copyright: All content on this site is written by me, except where explicitly stated. If you'd like to use an article I've written on your site you are free to do so providing you acknowledge me as the author, and link to the original post where possible.